1. Field of the Invention
The present invention relates to inflatable restraint devices used in automotive vehicles for restraining movement of an occupant and cushioning contact between the occupant and structural members of the vehicle during an accident. In particular, the invention relates to such restraint devices which are contained in a side panel of the vehicle and which provide protection from side impacts of the vehicle.
2. State of the Art
Inflatable restraint devices for restraining occupants of automotive vehicles involved in frontal collisions are of course well known. Such systems employ air bags which are inflated rapidly in response to a collision, with the inflated air bags providing a cushioning and restraint for the occupants from impact with the steering wheel, instrument panel and windshield of the vehicle. For examples of such systems see U.S. Pat. Nos. 3,642,303; 3,758,133 and 4,097,065.
The inflatable restraint systems of the prior art generally do little to provide essential protection to an occupant of a vehicle during accidents involving impact of the side of the vehicle. During side impact collisions, seat belts do little more than prevent occupants from impacting each other and prevent total ejection of an occupant from the vehicle. In a side impact collision the occupant is subject to dangerous contact with the side of the vehicle next to which the occupant is seated and the distinct possibility exists of partial ejection of and injury to the occupant's head, neck and shoulders through the window area of that side of the vehicle. Conventional restraint systems have not adequately addressed these problems.
Some limited protection in side impact collisions is afforded by conventional padding applied to the interior surfaces of the side panel, but space and comfort limitations along the interior of the side panel preclude use of sufficient padding depth to be of significant value in a moderate-to-severe accident. In U.S. Pat. No. 3,791,667, it was proposed to provide a housing recessed in a side panel of a vehicle, with the housing having an open side facing the interior of the vehicle. An elastomeric, stretchable membrane was secured over the open side of the housing, having its peripheral edges sealed to the housing. In a collision, gas under pressure was delivered to the housing to expand the membrane toward the interior of the vehicle to form a cushion for the torso of an occupant seated adjacent thereto. The system of U.S. Pat. No. 3,791,667 does not, however, provide any cushioning of the occupants' shoulders and head from impact with a window in the side panel, the window frame, the roof pillar adjacent the side of the window or the roof rail adjacent the upper side of the window. Nor does such system offer any restraint against the occupant's head and neck from being thrown through the window.
In U.S. Pat. No. 3,897,961, inflatable restraint apparatus is disclosed which include folded air bags stored in the roof structure of the vehicle. A torso bag is deployed from the roof of the vehicle toward the lap of the occupant. In addition, an inflatable side curtain bag is deployed from the roof to, at least theoretically, extend downward between the occupant and a side window in the side panel of the vehicle. If properly inflated and positioned, the side curtain would provide side cushioning of the head and shoulders of the occupant and inhibit movement of the occupant's head through the window or against the roof rail. Unfortunately, however, the source of gas for inflating both the torso bag and the curtain bag is located out of the passenger compartment, and a conduit extends from the gas source to the respective air bags.
To be effective in side impact collisions, a restraint system must offer essentially immediate padding and restraint to the entire flank of the occupant. Timing of air bag deployment is absolutely critical. In a typical crash, each millisecond delay represents about one-half inch of side panel or door penetration. The system of U.S. Pat. No. 3,897,961 has not been used commercially, and it is likely that delays in activating the gas generator and then of transmitting the gas to the air bags would be far too long for the system to work effectively. In addition, the system is bulky, relatively complex and would be excessively costly.
An even more complex system is disclosed in U.S. Pat. No. 3,687,485. An air bag is deployed downwardly from the roof structure of the vehicle toward the rear seat thereof. A series of pulleys and cables are provided for pulling a screen downwardly over the side window of the vehicle as the air bag is deployed. The system of Pat. No. 3,687,485 has not been used commercially possibly due to its excessive complexity or its potential to iflict injury during deployment.